linux/drivers/input/touchscreen/elants_i2c.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Elan Microelectronics touch panels with I2C interface
   4 *
   5 * Copyright (C) 2014 Elan Microelectronics Corporation.
   6 * Scott Liu <scott.liu@emc.com.tw>
   7 *
   8 * This code is partly based on hid-multitouch.c:
   9 *
  10 *  Copyright (c) 2010-2012 Stephane Chatty <chatty@enac.fr>
  11 *  Copyright (c) 2010-2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
  12 *  Copyright (c) 2010-2012 Ecole Nationale de l'Aviation Civile, France
  13 *
  14 * This code is partly based on i2c-hid.c:
  15 *
  16 * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
  17 * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
  18 * Copyright (c) 2012 Red Hat, Inc
  19 */
  20
  21
  22#include <linux/module.h>
  23#include <linux/input.h>
  24#include <linux/interrupt.h>
  25#include <linux/irq.h>
  26#include <linux/platform_device.h>
  27#include <linux/async.h>
  28#include <linux/i2c.h>
  29#include <linux/delay.h>
  30#include <linux/uaccess.h>
  31#include <linux/buffer_head.h>
  32#include <linux/slab.h>
  33#include <linux/firmware.h>
  34#include <linux/input/mt.h>
  35#include <linux/acpi.h>
  36#include <linux/of.h>
  37#include <linux/gpio/consumer.h>
  38#include <linux/regulator/consumer.h>
  39#include <asm/unaligned.h>
  40
  41/* Device, Driver information */
  42#define DEVICE_NAME     "elants_i2c"
  43
  44/* Convert from rows or columns into resolution */
  45#define ELAN_TS_RESOLUTION(n, m)   (((n) - 1) * (m))
  46
  47/* FW header data */
  48#define HEADER_SIZE             4
  49#define FW_HDR_TYPE             0
  50#define FW_HDR_COUNT            1
  51#define FW_HDR_LENGTH           2
  52
  53/* Buffer mode Queue Header information */
  54#define QUEUE_HEADER_SINGLE     0x62
  55#define QUEUE_HEADER_NORMAL     0X63
  56#define QUEUE_HEADER_WAIT       0x64
  57
  58/* Command header definition */
  59#define CMD_HEADER_WRITE        0x54
  60#define CMD_HEADER_READ         0x53
  61#define CMD_HEADER_6B_READ      0x5B
  62#define CMD_HEADER_RESP         0x52
  63#define CMD_HEADER_6B_RESP      0x9B
  64#define CMD_HEADER_HELLO        0x55
  65#define CMD_HEADER_REK          0x66
  66
  67/* FW position data */
  68#define PACKET_SIZE             55
  69#define MAX_CONTACT_NUM         10
  70#define FW_POS_HEADER           0
  71#define FW_POS_STATE            1
  72#define FW_POS_TOTAL            2
  73#define FW_POS_XY               3
  74#define FW_POS_CHECKSUM         34
  75#define FW_POS_WIDTH            35
  76#define FW_POS_PRESSURE         45
  77
  78#define HEADER_REPORT_10_FINGER 0x62
  79
  80/* Header (4 bytes) plus 3 fill 10-finger packets */
  81#define MAX_PACKET_SIZE         169
  82
  83#define BOOT_TIME_DELAY_MS      50
  84
  85/* FW read command, 0x53 0x?? 0x0, 0x01 */
  86#define E_ELAN_INFO_FW_VER      0x00
  87#define E_ELAN_INFO_BC_VER      0x10
  88#define E_ELAN_INFO_TEST_VER    0xE0
  89#define E_ELAN_INFO_FW_ID       0xF0
  90#define E_INFO_OSR              0xD6
  91#define E_INFO_PHY_SCAN         0xD7
  92#define E_INFO_PHY_DRIVER       0xD8
  93
  94#define MAX_RETRIES             3
  95#define MAX_FW_UPDATE_RETRIES   30
  96
  97#define ELAN_FW_PAGESIZE        132
  98
  99/* calibration timeout definition */
 100#define ELAN_CALI_TIMEOUT_MSEC  12000
 101
 102#define ELAN_POWERON_DELAY_USEC 500
 103#define ELAN_RESET_DELAY_MSEC   20
 104
 105enum elants_state {
 106        ELAN_STATE_NORMAL,
 107        ELAN_WAIT_QUEUE_HEADER,
 108        ELAN_WAIT_RECALIBRATION,
 109};
 110
 111enum elants_iap_mode {
 112        ELAN_IAP_OPERATIONAL,
 113        ELAN_IAP_RECOVERY,
 114};
 115
 116/* struct elants_data - represents state of Elan touchscreen device */
 117struct elants_data {
 118        struct i2c_client *client;
 119        struct input_dev *input;
 120
 121        struct regulator *vcc33;
 122        struct regulator *vccio;
 123        struct gpio_desc *reset_gpio;
 124
 125        u16 fw_version;
 126        u8 test_version;
 127        u8 solution_version;
 128        u8 bc_version;
 129        u8 iap_version;
 130        u16 hw_version;
 131        unsigned int x_res;     /* resolution in units/mm */
 132        unsigned int y_res;
 133        unsigned int x_max;
 134        unsigned int y_max;
 135
 136        enum elants_state state;
 137        enum elants_iap_mode iap_mode;
 138
 139        /* Guards against concurrent access to the device via sysfs */
 140        struct mutex sysfs_mutex;
 141
 142        u8 cmd_resp[HEADER_SIZE];
 143        struct completion cmd_done;
 144
 145        bool wake_irq_enabled;
 146        bool keep_power_in_suspend;
 147
 148        /* Must be last to be used for DMA operations */
 149        u8 buf[MAX_PACKET_SIZE] ____cacheline_aligned;
 150};
 151
 152static int elants_i2c_send(struct i2c_client *client,
 153                           const void *data, size_t size)
 154{
 155        int ret;
 156
 157        ret = i2c_master_send(client, data, size);
 158        if (ret == size)
 159                return 0;
 160
 161        if (ret >= 0)
 162                ret = -EIO;
 163
 164        dev_err(&client->dev, "%s failed (%*ph): %d\n",
 165                __func__, (int)size, data, ret);
 166
 167        return ret;
 168}
 169
 170static int elants_i2c_read(struct i2c_client *client, void *data, size_t size)
 171{
 172        int ret;
 173
 174        ret = i2c_master_recv(client, data, size);
 175        if (ret == size)
 176                return 0;
 177
 178        if (ret >= 0)
 179                ret = -EIO;
 180
 181        dev_err(&client->dev, "%s failed: %d\n", __func__, ret);
 182
 183        return ret;
 184}
 185
 186static int elants_i2c_execute_command(struct i2c_client *client,
 187                                      const u8 *cmd, size_t cmd_size,
 188                                      u8 *resp, size_t resp_size)
 189{
 190        struct i2c_msg msgs[2];
 191        int ret;
 192        u8 expected_response;
 193
 194        switch (cmd[0]) {
 195        case CMD_HEADER_READ:
 196                expected_response = CMD_HEADER_RESP;
 197                break;
 198
 199        case CMD_HEADER_6B_READ:
 200                expected_response = CMD_HEADER_6B_RESP;
 201                break;
 202
 203        default:
 204                dev_err(&client->dev, "%s: invalid command %*ph\n",
 205                        __func__, (int)cmd_size, cmd);
 206                return -EINVAL;
 207        }
 208
 209        msgs[0].addr = client->addr;
 210        msgs[0].flags = client->flags & I2C_M_TEN;
 211        msgs[0].len = cmd_size;
 212        msgs[0].buf = (u8 *)cmd;
 213
 214        msgs[1].addr = client->addr;
 215        msgs[1].flags = client->flags & I2C_M_TEN;
 216        msgs[1].flags |= I2C_M_RD;
 217        msgs[1].len = resp_size;
 218        msgs[1].buf = resp;
 219
 220        ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 221        if (ret < 0)
 222                return ret;
 223
 224        if (ret != ARRAY_SIZE(msgs) || resp[FW_HDR_TYPE] != expected_response)
 225                return -EIO;
 226
 227        return 0;
 228}
 229
 230static int elants_i2c_calibrate(struct elants_data *ts)
 231{
 232        struct i2c_client *client = ts->client;
 233        int ret, error;
 234        static const u8 w_flashkey[] = { 0x54, 0xC0, 0xE1, 0x5A };
 235        static const u8 rek[] = { 0x54, 0x29, 0x00, 0x01 };
 236        static const u8 rek_resp[] = { CMD_HEADER_REK, 0x66, 0x66, 0x66 };
 237
 238        disable_irq(client->irq);
 239
 240        ts->state = ELAN_WAIT_RECALIBRATION;
 241        reinit_completion(&ts->cmd_done);
 242
 243        elants_i2c_send(client, w_flashkey, sizeof(w_flashkey));
 244        elants_i2c_send(client, rek, sizeof(rek));
 245
 246        enable_irq(client->irq);
 247
 248        ret = wait_for_completion_interruptible_timeout(&ts->cmd_done,
 249                                msecs_to_jiffies(ELAN_CALI_TIMEOUT_MSEC));
 250
 251        ts->state = ELAN_STATE_NORMAL;
 252
 253        if (ret <= 0) {
 254                error = ret < 0 ? ret : -ETIMEDOUT;
 255                dev_err(&client->dev,
 256                        "error while waiting for calibration to complete: %d\n",
 257                        error);
 258                return error;
 259        }
 260
 261        if (memcmp(rek_resp, ts->cmd_resp, sizeof(rek_resp))) {
 262                dev_err(&client->dev,
 263                        "unexpected calibration response: %*ph\n",
 264                        (int)sizeof(ts->cmd_resp), ts->cmd_resp);
 265                return -EINVAL;
 266        }
 267
 268        return 0;
 269}
 270
 271static int elants_i2c_sw_reset(struct i2c_client *client)
 272{
 273        const u8 soft_rst_cmd[] = { 0x77, 0x77, 0x77, 0x77 };
 274        int error;
 275
 276        error = elants_i2c_send(client, soft_rst_cmd,
 277                                sizeof(soft_rst_cmd));
 278        if (error) {
 279                dev_err(&client->dev, "software reset failed: %d\n", error);
 280                return error;
 281        }
 282
 283        /*
 284         * We should wait at least 10 msec (but no more than 40) before
 285         * sending fastboot or IAP command to the device.
 286         */
 287        msleep(30);
 288
 289        return 0;
 290}
 291
 292static u16 elants_i2c_parse_version(u8 *buf)
 293{
 294        return get_unaligned_be32(buf) >> 4;
 295}
 296
 297static int elants_i2c_query_hw_version(struct elants_data *ts)
 298{
 299        struct i2c_client *client = ts->client;
 300        int error, retry_cnt;
 301        const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_FW_ID, 0x00, 0x01 };
 302        u8 resp[HEADER_SIZE];
 303
 304        for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
 305                error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
 306                                                   resp, sizeof(resp));
 307                if (!error) {
 308                        ts->hw_version = elants_i2c_parse_version(resp);
 309                        if (ts->hw_version != 0xffff)
 310                                return 0;
 311                }
 312
 313                dev_dbg(&client->dev, "read fw id error=%d, buf=%*phC\n",
 314                        error, (int)sizeof(resp), resp);
 315        }
 316
 317        if (error) {
 318                dev_err(&client->dev,
 319                        "Failed to read fw id: %d\n", error);
 320                return error;
 321        }
 322
 323        dev_err(&client->dev, "Invalid fw id: %#04x\n", ts->hw_version);
 324
 325        return -EINVAL;
 326}
 327
 328static int elants_i2c_query_fw_version(struct elants_data *ts)
 329{
 330        struct i2c_client *client = ts->client;
 331        int error, retry_cnt;
 332        const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_FW_VER, 0x00, 0x01 };
 333        u8 resp[HEADER_SIZE];
 334
 335        for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
 336                error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
 337                                                   resp, sizeof(resp));
 338                if (!error) {
 339                        ts->fw_version = elants_i2c_parse_version(resp);
 340                        if (ts->fw_version != 0x0000 &&
 341                            ts->fw_version != 0xffff)
 342                                return 0;
 343                }
 344
 345                dev_dbg(&client->dev, "read fw version error=%d, buf=%*phC\n",
 346                        error, (int)sizeof(resp), resp);
 347        }
 348
 349        dev_err(&client->dev,
 350                "Failed to read fw version or fw version is invalid\n");
 351
 352        return -EINVAL;
 353}
 354
 355static int elants_i2c_query_test_version(struct elants_data *ts)
 356{
 357        struct i2c_client *client = ts->client;
 358        int error, retry_cnt;
 359        u16 version;
 360        const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_TEST_VER, 0x00, 0x01 };
 361        u8 resp[HEADER_SIZE];
 362
 363        for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
 364                error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
 365                                                   resp, sizeof(resp));
 366                if (!error) {
 367                        version = elants_i2c_parse_version(resp);
 368                        ts->test_version = version >> 8;
 369                        ts->solution_version = version & 0xff;
 370
 371                        return 0;
 372                }
 373
 374                dev_dbg(&client->dev,
 375                        "read test version error rc=%d, buf=%*phC\n",
 376                        error, (int)sizeof(resp), resp);
 377        }
 378
 379        dev_err(&client->dev, "Failed to read test version\n");
 380
 381        return -EINVAL;
 382}
 383
 384static int elants_i2c_query_bc_version(struct elants_data *ts)
 385{
 386        struct i2c_client *client = ts->client;
 387        const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_BC_VER, 0x00, 0x01 };
 388        u8 resp[HEADER_SIZE];
 389        u16 version;
 390        int error;
 391
 392        error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
 393                                           resp, sizeof(resp));
 394        if (error) {
 395                dev_err(&client->dev,
 396                        "read BC version error=%d, buf=%*phC\n",
 397                        error, (int)sizeof(resp), resp);
 398                return error;
 399        }
 400
 401        version = elants_i2c_parse_version(resp);
 402        ts->bc_version = version >> 8;
 403        ts->iap_version = version & 0xff;
 404
 405        return 0;
 406}
 407
 408static int elants_i2c_query_ts_info(struct elants_data *ts)
 409{
 410        struct i2c_client *client = ts->client;
 411        int error;
 412        u8 resp[17];
 413        u16 phy_x, phy_y, rows, cols, osr;
 414        const u8 get_resolution_cmd[] = {
 415                CMD_HEADER_6B_READ, 0x00, 0x00, 0x00, 0x00, 0x00
 416        };
 417        const u8 get_osr_cmd[] = {
 418                CMD_HEADER_READ, E_INFO_OSR, 0x00, 0x01
 419        };
 420        const u8 get_physical_scan_cmd[] = {
 421                CMD_HEADER_READ, E_INFO_PHY_SCAN, 0x00, 0x01
 422        };
 423        const u8 get_physical_drive_cmd[] = {
 424                CMD_HEADER_READ, E_INFO_PHY_DRIVER, 0x00, 0x01
 425        };
 426
 427        /* Get trace number */
 428        error = elants_i2c_execute_command(client,
 429                                           get_resolution_cmd,
 430                                           sizeof(get_resolution_cmd),
 431                                           resp, sizeof(resp));
 432        if (error) {
 433                dev_err(&client->dev, "get resolution command failed: %d\n",
 434                        error);
 435                return error;
 436        }
 437
 438        rows = resp[2] + resp[6] + resp[10];
 439        cols = resp[3] + resp[7] + resp[11];
 440
 441        /* Process mm_to_pixel information */
 442        error = elants_i2c_execute_command(client,
 443                                           get_osr_cmd, sizeof(get_osr_cmd),
 444                                           resp, sizeof(resp));
 445        if (error) {
 446                dev_err(&client->dev, "get osr command failed: %d\n",
 447                        error);
 448                return error;
 449        }
 450
 451        osr = resp[3];
 452
 453        error = elants_i2c_execute_command(client,
 454                                           get_physical_scan_cmd,
 455                                           sizeof(get_physical_scan_cmd),
 456                                           resp, sizeof(resp));
 457        if (error) {
 458                dev_err(&client->dev, "get physical scan command failed: %d\n",
 459                        error);
 460                return error;
 461        }
 462
 463        phy_x = get_unaligned_be16(&resp[2]);
 464
 465        error = elants_i2c_execute_command(client,
 466                                           get_physical_drive_cmd,
 467                                           sizeof(get_physical_drive_cmd),
 468                                           resp, sizeof(resp));
 469        if (error) {
 470                dev_err(&client->dev, "get physical drive command failed: %d\n",
 471                        error);
 472                return error;
 473        }
 474
 475        phy_y = get_unaligned_be16(&resp[2]);
 476
 477        dev_dbg(&client->dev, "phy_x=%d, phy_y=%d\n", phy_x, phy_y);
 478
 479        if (rows == 0 || cols == 0 || osr == 0) {
 480                dev_warn(&client->dev,
 481                         "invalid trace number data: %d, %d, %d\n",
 482                         rows, cols, osr);
 483        } else {
 484                /* translate trace number to TS resolution */
 485                ts->x_max = ELAN_TS_RESOLUTION(rows, osr);
 486                ts->x_res = DIV_ROUND_CLOSEST(ts->x_max, phy_x);
 487                ts->y_max = ELAN_TS_RESOLUTION(cols, osr);
 488                ts->y_res = DIV_ROUND_CLOSEST(ts->y_max, phy_y);
 489        }
 490
 491        return 0;
 492}
 493
 494static int elants_i2c_fastboot(struct i2c_client *client)
 495{
 496        const u8 boot_cmd[] = { 0x4D, 0x61, 0x69, 0x6E };
 497        int error;
 498
 499        error = elants_i2c_send(client, boot_cmd, sizeof(boot_cmd));
 500        if (error) {
 501                dev_err(&client->dev, "boot failed: %d\n", error);
 502                return error;
 503        }
 504
 505        dev_dbg(&client->dev, "boot success -- 0x%x\n", client->addr);
 506        return 0;
 507}
 508
 509static int elants_i2c_initialize(struct elants_data *ts)
 510{
 511        struct i2c_client *client = ts->client;
 512        int error, error2, retry_cnt;
 513        const u8 hello_packet[] = { 0x55, 0x55, 0x55, 0x55 };
 514        const u8 recov_packet[] = { 0x55, 0x55, 0x80, 0x80 };
 515        u8 buf[HEADER_SIZE];
 516
 517        for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
 518                error = elants_i2c_sw_reset(client);
 519                if (error) {
 520                        /* Continue initializing if it's the last try */
 521                        if (retry_cnt < MAX_RETRIES - 1)
 522                                continue;
 523                }
 524
 525                error = elants_i2c_fastboot(client);
 526                if (error) {
 527                        /* Continue initializing if it's the last try */
 528                        if (retry_cnt < MAX_RETRIES - 1)
 529                                continue;
 530                }
 531
 532                /* Wait for Hello packet */
 533                msleep(BOOT_TIME_DELAY_MS);
 534
 535                error = elants_i2c_read(client, buf, sizeof(buf));
 536                if (error) {
 537                        dev_err(&client->dev,
 538                                "failed to read 'hello' packet: %d\n", error);
 539                } else if (!memcmp(buf, hello_packet, sizeof(hello_packet))) {
 540                        ts->iap_mode = ELAN_IAP_OPERATIONAL;
 541                        break;
 542                } else if (!memcmp(buf, recov_packet, sizeof(recov_packet))) {
 543                        /*
 544                         * Setting error code will mark device
 545                         * in recovery mode below.
 546                         */
 547                        error = -EIO;
 548                        break;
 549                } else {
 550                        error = -EINVAL;
 551                        dev_err(&client->dev,
 552                                "invalid 'hello' packet: %*ph\n",
 553                                (int)sizeof(buf), buf);
 554                }
 555        }
 556
 557        /* hw version is available even if device in recovery state */
 558        error2 = elants_i2c_query_hw_version(ts);
 559        if (!error)
 560                error = error2;
 561
 562        if (!error)
 563                error = elants_i2c_query_fw_version(ts);
 564        if (!error)
 565                error = elants_i2c_query_test_version(ts);
 566        if (!error)
 567                error = elants_i2c_query_bc_version(ts);
 568        if (!error)
 569                error = elants_i2c_query_ts_info(ts);
 570
 571        if (error)
 572                ts->iap_mode = ELAN_IAP_RECOVERY;
 573
 574        return 0;
 575}
 576
 577/*
 578 * Firmware update interface.
 579 */
 580
 581static int elants_i2c_fw_write_page(struct i2c_client *client,
 582                                    const void *page)
 583{
 584        const u8 ack_ok[] = { 0xaa, 0xaa };
 585        u8 buf[2];
 586        int retry;
 587        int error;
 588
 589        for (retry = 0; retry < MAX_FW_UPDATE_RETRIES; retry++) {
 590                error = elants_i2c_send(client, page, ELAN_FW_PAGESIZE);
 591                if (error) {
 592                        dev_err(&client->dev,
 593                                "IAP Write Page failed: %d\n", error);
 594                        continue;
 595                }
 596
 597                error = elants_i2c_read(client, buf, 2);
 598                if (error) {
 599                        dev_err(&client->dev,
 600                                "IAP Ack read failed: %d\n", error);
 601                        return error;
 602                }
 603
 604                if (!memcmp(buf, ack_ok, sizeof(ack_ok)))
 605                        return 0;
 606
 607                error = -EIO;
 608                dev_err(&client->dev,
 609                        "IAP Get Ack Error [%02x:%02x]\n",
 610                        buf[0], buf[1]);
 611        }
 612
 613        return error;
 614}
 615
 616static int elants_i2c_do_update_firmware(struct i2c_client *client,
 617                                         const struct firmware *fw,
 618                                         bool force)
 619{
 620        const u8 enter_iap[] = { 0x45, 0x49, 0x41, 0x50 };
 621        const u8 enter_iap2[] = { 0x54, 0x00, 0x12, 0x34 };
 622        const u8 iap_ack[] = { 0x55, 0xaa, 0x33, 0xcc };
 623        const u8 close_idle[] = {0x54, 0x2c, 0x01, 0x01};
 624        u8 buf[HEADER_SIZE];
 625        u16 send_id;
 626        int page, n_fw_pages;
 627        int error;
 628
 629        /* Recovery mode detection! */
 630        if (force) {
 631                dev_dbg(&client->dev, "Recovery mode procedure\n");
 632                error = elants_i2c_send(client, enter_iap2, sizeof(enter_iap2));
 633        } else {
 634                /* Start IAP Procedure */
 635                dev_dbg(&client->dev, "Normal IAP procedure\n");
 636                /* Close idle mode */
 637                error = elants_i2c_send(client, close_idle, sizeof(close_idle));
 638                if (error)
 639                        dev_err(&client->dev, "Failed close idle: %d\n", error);
 640                msleep(60);
 641                elants_i2c_sw_reset(client);
 642                msleep(20);
 643                error = elants_i2c_send(client, enter_iap, sizeof(enter_iap));
 644        }
 645
 646        if (error) {
 647                dev_err(&client->dev, "failed to enter IAP mode: %d\n", error);
 648                return error;
 649        }
 650
 651        msleep(20);
 652
 653        /* check IAP state */
 654        error = elants_i2c_read(client, buf, 4);
 655        if (error) {
 656                dev_err(&client->dev,
 657                        "failed to read IAP acknowledgement: %d\n",
 658                        error);
 659                return error;
 660        }
 661
 662        if (memcmp(buf, iap_ack, sizeof(iap_ack))) {
 663                dev_err(&client->dev,
 664                        "failed to enter IAP: %*ph (expected %*ph)\n",
 665                        (int)sizeof(buf), buf, (int)sizeof(iap_ack), iap_ack);
 666                return -EIO;
 667        }
 668
 669        dev_info(&client->dev, "successfully entered IAP mode");
 670
 671        send_id = client->addr;
 672        error = elants_i2c_send(client, &send_id, 1);
 673        if (error) {
 674                dev_err(&client->dev, "sending dummy byte failed: %d\n",
 675                        error);
 676                return error;
 677        }
 678
 679        /* Clear the last page of Master */
 680        error = elants_i2c_send(client, fw->data, ELAN_FW_PAGESIZE);
 681        if (error) {
 682                dev_err(&client->dev, "clearing of the last page failed: %d\n",
 683                        error);
 684                return error;
 685        }
 686
 687        error = elants_i2c_read(client, buf, 2);
 688        if (error) {
 689                dev_err(&client->dev,
 690                        "failed to read ACK for clearing the last page: %d\n",
 691                        error);
 692                return error;
 693        }
 694
 695        n_fw_pages = fw->size / ELAN_FW_PAGESIZE;
 696        dev_dbg(&client->dev, "IAP Pages = %d\n", n_fw_pages);
 697
 698        for (page = 0; page < n_fw_pages; page++) {
 699                error = elants_i2c_fw_write_page(client,
 700                                        fw->data + page * ELAN_FW_PAGESIZE);
 701                if (error) {
 702                        dev_err(&client->dev,
 703                                "failed to write FW page %d: %d\n",
 704                                page, error);
 705                        return error;
 706                }
 707        }
 708
 709        /* Old iap needs to wait 200ms for WDT and rest is for hello packets */
 710        msleep(300);
 711
 712        dev_info(&client->dev, "firmware update completed\n");
 713        return 0;
 714}
 715
 716static int elants_i2c_fw_update(struct elants_data *ts)
 717{
 718        struct i2c_client *client = ts->client;
 719        const struct firmware *fw;
 720        char *fw_name;
 721        int error;
 722
 723        fw_name = kasprintf(GFP_KERNEL, "elants_i2c_%04x.bin", ts->hw_version);
 724        if (!fw_name)
 725                return -ENOMEM;
 726
 727        dev_info(&client->dev, "requesting fw name = %s\n", fw_name);
 728        error = request_firmware(&fw, fw_name, &client->dev);
 729        kfree(fw_name);
 730        if (error) {
 731                dev_err(&client->dev, "failed to request firmware: %d\n",
 732                        error);
 733                return error;
 734        }
 735
 736        if (fw->size % ELAN_FW_PAGESIZE) {
 737                dev_err(&client->dev, "invalid firmware length: %zu\n",
 738                        fw->size);
 739                error = -EINVAL;
 740                goto out;
 741        }
 742
 743        disable_irq(client->irq);
 744
 745        error = elants_i2c_do_update_firmware(client, fw,
 746                                        ts->iap_mode == ELAN_IAP_RECOVERY);
 747        if (error) {
 748                dev_err(&client->dev, "firmware update failed: %d\n", error);
 749                ts->iap_mode = ELAN_IAP_RECOVERY;
 750                goto out_enable_irq;
 751        }
 752
 753        error = elants_i2c_initialize(ts);
 754        if (error) {
 755                dev_err(&client->dev,
 756                        "failed to initialize device after firmware update: %d\n",
 757                        error);
 758                ts->iap_mode = ELAN_IAP_RECOVERY;
 759                goto out_enable_irq;
 760        }
 761
 762        ts->iap_mode = ELAN_IAP_OPERATIONAL;
 763
 764out_enable_irq:
 765        ts->state = ELAN_STATE_NORMAL;
 766        enable_irq(client->irq);
 767        msleep(100);
 768
 769        if (!error)
 770                elants_i2c_calibrate(ts);
 771out:
 772        release_firmware(fw);
 773        return error;
 774}
 775
 776/*
 777 * Event reporting.
 778 */
 779
 780static void elants_i2c_mt_event(struct elants_data *ts, u8 *buf)
 781{
 782        struct input_dev *input = ts->input;
 783        unsigned int n_fingers;
 784        u16 finger_state;
 785        int i;
 786
 787        n_fingers = buf[FW_POS_STATE + 1] & 0x0f;
 788        finger_state = ((buf[FW_POS_STATE + 1] & 0x30) << 4) |
 789                        buf[FW_POS_STATE];
 790
 791        dev_dbg(&ts->client->dev,
 792                "n_fingers: %u, state: %04x\n",  n_fingers, finger_state);
 793
 794        for (i = 0; i < MAX_CONTACT_NUM && n_fingers; i++) {
 795                if (finger_state & 1) {
 796                        unsigned int x, y, p, w;
 797                        u8 *pos;
 798
 799                        pos = &buf[FW_POS_XY + i * 3];
 800                        x = (((u16)pos[0] & 0xf0) << 4) | pos[1];
 801                        y = (((u16)pos[0] & 0x0f) << 8) | pos[2];
 802                        p = buf[FW_POS_PRESSURE + i];
 803                        w = buf[FW_POS_WIDTH + i];
 804
 805                        dev_dbg(&ts->client->dev, "i=%d x=%d y=%d p=%d w=%d\n",
 806                                i, x, y, p, w);
 807
 808                        input_mt_slot(input, i);
 809                        input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
 810                        input_event(input, EV_ABS, ABS_MT_POSITION_X, x);
 811                        input_event(input, EV_ABS, ABS_MT_POSITION_Y, y);
 812                        input_event(input, EV_ABS, ABS_MT_PRESSURE, p);
 813                        input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, w);
 814
 815                        n_fingers--;
 816                }
 817
 818                finger_state >>= 1;
 819        }
 820
 821        input_mt_sync_frame(input);
 822        input_sync(input);
 823}
 824
 825static u8 elants_i2c_calculate_checksum(u8 *buf)
 826{
 827        u8 checksum = 0;
 828        u8 i;
 829
 830        for (i = 0; i < FW_POS_CHECKSUM; i++)
 831                checksum += buf[i];
 832
 833        return checksum;
 834}
 835
 836static void elants_i2c_event(struct elants_data *ts, u8 *buf)
 837{
 838        u8 checksum = elants_i2c_calculate_checksum(buf);
 839
 840        if (unlikely(buf[FW_POS_CHECKSUM] != checksum))
 841                dev_warn(&ts->client->dev,
 842                         "%s: invalid checksum for packet %02x: %02x vs. %02x\n",
 843                         __func__, buf[FW_POS_HEADER],
 844                         checksum, buf[FW_POS_CHECKSUM]);
 845        else if (unlikely(buf[FW_POS_HEADER] != HEADER_REPORT_10_FINGER))
 846                dev_warn(&ts->client->dev,
 847                         "%s: unknown packet type: %02x\n",
 848                         __func__, buf[FW_POS_HEADER]);
 849        else
 850                elants_i2c_mt_event(ts, buf);
 851}
 852
 853static irqreturn_t elants_i2c_irq(int irq, void *_dev)
 854{
 855        const u8 wait_packet[] = { 0x64, 0x64, 0x64, 0x64 };
 856        struct elants_data *ts = _dev;
 857        struct i2c_client *client = ts->client;
 858        int report_count, report_len;
 859        int i;
 860        int len;
 861
 862        len = i2c_master_recv_dmasafe(client, ts->buf, sizeof(ts->buf));
 863        if (len < 0) {
 864                dev_err(&client->dev, "%s: failed to read data: %d\n",
 865                        __func__, len);
 866                goto out;
 867        }
 868
 869        dev_dbg(&client->dev, "%s: packet %*ph\n",
 870                __func__, HEADER_SIZE, ts->buf);
 871
 872        switch (ts->state) {
 873        case ELAN_WAIT_RECALIBRATION:
 874                if (ts->buf[FW_HDR_TYPE] == CMD_HEADER_REK) {
 875                        memcpy(ts->cmd_resp, ts->buf, sizeof(ts->cmd_resp));
 876                        complete(&ts->cmd_done);
 877                        ts->state = ELAN_STATE_NORMAL;
 878                }
 879                break;
 880
 881        case ELAN_WAIT_QUEUE_HEADER:
 882                if (ts->buf[FW_HDR_TYPE] != QUEUE_HEADER_NORMAL)
 883                        break;
 884
 885                ts->state = ELAN_STATE_NORMAL;
 886                /* fall through */
 887
 888        case ELAN_STATE_NORMAL:
 889
 890                switch (ts->buf[FW_HDR_TYPE]) {
 891                case CMD_HEADER_HELLO:
 892                case CMD_HEADER_RESP:
 893                case CMD_HEADER_REK:
 894                        break;
 895
 896                case QUEUE_HEADER_WAIT:
 897                        if (memcmp(ts->buf, wait_packet, sizeof(wait_packet))) {
 898                                dev_err(&client->dev,
 899                                        "invalid wait packet %*ph\n",
 900                                        HEADER_SIZE, ts->buf);
 901                        } else {
 902                                ts->state = ELAN_WAIT_QUEUE_HEADER;
 903                                udelay(30);
 904                        }
 905                        break;
 906
 907                case QUEUE_HEADER_SINGLE:
 908                        elants_i2c_event(ts, &ts->buf[HEADER_SIZE]);
 909                        break;
 910
 911                case QUEUE_HEADER_NORMAL:
 912                        report_count = ts->buf[FW_HDR_COUNT];
 913                        if (report_count == 0 || report_count > 3) {
 914                                dev_err(&client->dev,
 915                                        "bad report count: %*ph\n",
 916                                        HEADER_SIZE, ts->buf);
 917                                break;
 918                        }
 919
 920                        report_len = ts->buf[FW_HDR_LENGTH] / report_count;
 921                        if (report_len != PACKET_SIZE) {
 922                                dev_err(&client->dev,
 923                                        "mismatching report length: %*ph\n",
 924                                        HEADER_SIZE, ts->buf);
 925                                break;
 926                        }
 927
 928                        for (i = 0; i < report_count; i++) {
 929                                u8 *buf = ts->buf + HEADER_SIZE +
 930                                                        i * PACKET_SIZE;
 931                                elants_i2c_event(ts, buf);
 932                        }
 933                        break;
 934
 935                default:
 936                        dev_err(&client->dev, "unknown packet %*ph\n",
 937                                HEADER_SIZE, ts->buf);
 938                        break;
 939                }
 940                break;
 941        }
 942
 943out:
 944        return IRQ_HANDLED;
 945}
 946
 947/*
 948 * sysfs interface
 949 */
 950static ssize_t calibrate_store(struct device *dev,
 951                               struct device_attribute *attr,
 952                              const char *buf, size_t count)
 953{
 954        struct i2c_client *client = to_i2c_client(dev);
 955        struct elants_data *ts = i2c_get_clientdata(client);
 956        int error;
 957
 958        error = mutex_lock_interruptible(&ts->sysfs_mutex);
 959        if (error)
 960                return error;
 961
 962        error = elants_i2c_calibrate(ts);
 963
 964        mutex_unlock(&ts->sysfs_mutex);
 965        return error ?: count;
 966}
 967
 968static ssize_t write_update_fw(struct device *dev,
 969                               struct device_attribute *attr,
 970                               const char *buf, size_t count)
 971{
 972        struct i2c_client *client = to_i2c_client(dev);
 973        struct elants_data *ts = i2c_get_clientdata(client);
 974        int error;
 975
 976        error = mutex_lock_interruptible(&ts->sysfs_mutex);
 977        if (error)
 978                return error;
 979
 980        error = elants_i2c_fw_update(ts);
 981        dev_dbg(dev, "firmware update result: %d\n", error);
 982
 983        mutex_unlock(&ts->sysfs_mutex);
 984        return error ?: count;
 985}
 986
 987static ssize_t show_iap_mode(struct device *dev,
 988                             struct device_attribute *attr, char *buf)
 989{
 990        struct i2c_client *client = to_i2c_client(dev);
 991        struct elants_data *ts = i2c_get_clientdata(client);
 992
 993        return sprintf(buf, "%s\n",
 994                       ts->iap_mode == ELAN_IAP_OPERATIONAL ?
 995                                "Normal" : "Recovery");
 996}
 997
 998static DEVICE_ATTR_WO(calibrate);
 999static DEVICE_ATTR(iap_mode, S_IRUGO, show_iap_mode, NULL);
1000static DEVICE_ATTR(update_fw, S_IWUSR, NULL, write_update_fw);
1001
1002struct elants_version_attribute {
1003        struct device_attribute dattr;
1004        size_t field_offset;
1005        size_t field_size;
1006};
1007
1008#define __ELANTS_FIELD_SIZE(_field)                                     \
1009        sizeof(((struct elants_data *)NULL)->_field)
1010#define __ELANTS_VERIFY_SIZE(_field)                                    \
1011        (BUILD_BUG_ON_ZERO(__ELANTS_FIELD_SIZE(_field) > 2) +           \
1012         __ELANTS_FIELD_SIZE(_field))
1013#define ELANTS_VERSION_ATTR(_field)                                     \
1014        struct elants_version_attribute elants_ver_attr_##_field = {    \
1015                .dattr = __ATTR(_field, S_IRUGO,                        \
1016                                elants_version_attribute_show, NULL),   \
1017                .field_offset = offsetof(struct elants_data, _field),   \
1018                .field_size = __ELANTS_VERIFY_SIZE(_field),             \
1019        }
1020
1021static ssize_t elants_version_attribute_show(struct device *dev,
1022                                             struct device_attribute *dattr,
1023                                             char *buf)
1024{
1025        struct i2c_client *client = to_i2c_client(dev);
1026        struct elants_data *ts = i2c_get_clientdata(client);
1027        struct elants_version_attribute *attr =
1028                container_of(dattr, struct elants_version_attribute, dattr);
1029        u8 *field = (u8 *)((char *)ts + attr->field_offset);
1030        unsigned int fmt_size;
1031        unsigned int val;
1032
1033        if (attr->field_size == 1) {
1034                val = *field;
1035                fmt_size = 2; /* 2 HEX digits */
1036        } else {
1037                val = *(u16 *)field;
1038                fmt_size = 4; /* 4 HEX digits */
1039        }
1040
1041        return sprintf(buf, "%0*x\n", fmt_size, val);
1042}
1043
1044static ELANTS_VERSION_ATTR(fw_version);
1045static ELANTS_VERSION_ATTR(hw_version);
1046static ELANTS_VERSION_ATTR(test_version);
1047static ELANTS_VERSION_ATTR(solution_version);
1048static ELANTS_VERSION_ATTR(bc_version);
1049static ELANTS_VERSION_ATTR(iap_version);
1050
1051static struct attribute *elants_attributes[] = {
1052        &dev_attr_calibrate.attr,
1053        &dev_attr_update_fw.attr,
1054        &dev_attr_iap_mode.attr,
1055
1056        &elants_ver_attr_fw_version.dattr.attr,
1057        &elants_ver_attr_hw_version.dattr.attr,
1058        &elants_ver_attr_test_version.dattr.attr,
1059        &elants_ver_attr_solution_version.dattr.attr,
1060        &elants_ver_attr_bc_version.dattr.attr,
1061        &elants_ver_attr_iap_version.dattr.attr,
1062        NULL
1063};
1064
1065static const struct attribute_group elants_attribute_group = {
1066        .attrs = elants_attributes,
1067};
1068
1069static int elants_i2c_power_on(struct elants_data *ts)
1070{
1071        int error;
1072
1073        /*
1074         * If we do not have reset gpio assume platform firmware
1075         * controls regulators and does power them on for us.
1076         */
1077        if (IS_ERR_OR_NULL(ts->reset_gpio))
1078                return 0;
1079
1080        gpiod_set_value_cansleep(ts->reset_gpio, 1);
1081
1082        error = regulator_enable(ts->vcc33);
1083        if (error) {
1084                dev_err(&ts->client->dev,
1085                        "failed to enable vcc33 regulator: %d\n",
1086                        error);
1087                goto release_reset_gpio;
1088        }
1089
1090        error = regulator_enable(ts->vccio);
1091        if (error) {
1092                dev_err(&ts->client->dev,
1093                        "failed to enable vccio regulator: %d\n",
1094                        error);
1095                regulator_disable(ts->vcc33);
1096                goto release_reset_gpio;
1097        }
1098
1099        /*
1100         * We need to wait a bit after powering on controller before
1101         * we are allowed to release reset GPIO.
1102         */
1103        udelay(ELAN_POWERON_DELAY_USEC);
1104
1105release_reset_gpio:
1106        gpiod_set_value_cansleep(ts->reset_gpio, 0);
1107        if (error)
1108                return error;
1109
1110        msleep(ELAN_RESET_DELAY_MSEC);
1111
1112        return 0;
1113}
1114
1115static void elants_i2c_power_off(void *_data)
1116{
1117        struct elants_data *ts = _data;
1118
1119        if (!IS_ERR_OR_NULL(ts->reset_gpio)) {
1120                /*
1121                 * Activate reset gpio to prevent leakage through the
1122                 * pin once we shut off power to the controller.
1123                 */
1124                gpiod_set_value_cansleep(ts->reset_gpio, 1);
1125                regulator_disable(ts->vccio);
1126                regulator_disable(ts->vcc33);
1127        }
1128}
1129
1130static int elants_i2c_probe(struct i2c_client *client,
1131                            const struct i2c_device_id *id)
1132{
1133        union i2c_smbus_data dummy;
1134        struct elants_data *ts;
1135        unsigned long irqflags;
1136        int error;
1137
1138        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
1139                dev_err(&client->dev,
1140                        "%s: i2c check functionality error\n", DEVICE_NAME);
1141                return -ENXIO;
1142        }
1143
1144        ts = devm_kzalloc(&client->dev, sizeof(struct elants_data), GFP_KERNEL);
1145        if (!ts)
1146                return -ENOMEM;
1147
1148        mutex_init(&ts->sysfs_mutex);
1149        init_completion(&ts->cmd_done);
1150
1151        ts->client = client;
1152        i2c_set_clientdata(client, ts);
1153
1154        ts->vcc33 = devm_regulator_get(&client->dev, "vcc33");
1155        if (IS_ERR(ts->vcc33)) {
1156                error = PTR_ERR(ts->vcc33);
1157                if (error != -EPROBE_DEFER)
1158                        dev_err(&client->dev,
1159                                "Failed to get 'vcc33' regulator: %d\n",
1160                                error);
1161                return error;
1162        }
1163
1164        ts->vccio = devm_regulator_get(&client->dev, "vccio");
1165        if (IS_ERR(ts->vccio)) {
1166                error = PTR_ERR(ts->vccio);
1167                if (error != -EPROBE_DEFER)
1168                        dev_err(&client->dev,
1169                                "Failed to get 'vccio' regulator: %d\n",
1170                                error);
1171                return error;
1172        }
1173
1174        ts->reset_gpio = devm_gpiod_get(&client->dev, "reset", GPIOD_OUT_LOW);
1175        if (IS_ERR(ts->reset_gpio)) {
1176                error = PTR_ERR(ts->reset_gpio);
1177
1178                if (error == -EPROBE_DEFER)
1179                        return error;
1180
1181                if (error != -ENOENT && error != -ENOSYS) {
1182                        dev_err(&client->dev,
1183                                "failed to get reset gpio: %d\n",
1184                                error);
1185                        return error;
1186                }
1187
1188                ts->keep_power_in_suspend = true;
1189        }
1190
1191        error = elants_i2c_power_on(ts);
1192        if (error)
1193                return error;
1194
1195        error = devm_add_action(&client->dev, elants_i2c_power_off, ts);
1196        if (error) {
1197                dev_err(&client->dev,
1198                        "failed to install power off action: %d\n", error);
1199                elants_i2c_power_off(ts);
1200                return error;
1201        }
1202
1203        /* Make sure there is something at this address */
1204        if (i2c_smbus_xfer(client->adapter, client->addr, 0,
1205                           I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy) < 0) {
1206                dev_err(&client->dev, "nothing at this address\n");
1207                return -ENXIO;
1208        }
1209
1210        error = elants_i2c_initialize(ts);
1211        if (error) {
1212                dev_err(&client->dev, "failed to initialize: %d\n", error);
1213                return error;
1214        }
1215
1216        ts->input = devm_input_allocate_device(&client->dev);
1217        if (!ts->input) {
1218                dev_err(&client->dev, "Failed to allocate input device\n");
1219                return -ENOMEM;
1220        }
1221
1222        ts->input->name = "Elan Touchscreen";
1223        ts->input->id.bustype = BUS_I2C;
1224
1225        __set_bit(BTN_TOUCH, ts->input->keybit);
1226        __set_bit(EV_ABS, ts->input->evbit);
1227        __set_bit(EV_KEY, ts->input->evbit);
1228
1229        /* Single touch input params setup */
1230        input_set_abs_params(ts->input, ABS_X, 0, ts->x_max, 0, 0);
1231        input_set_abs_params(ts->input, ABS_Y, 0, ts->y_max, 0, 0);
1232        input_set_abs_params(ts->input, ABS_PRESSURE, 0, 255, 0, 0);
1233        input_abs_set_res(ts->input, ABS_X, ts->x_res);
1234        input_abs_set_res(ts->input, ABS_Y, ts->y_res);
1235
1236        /* Multitouch input params setup */
1237        error = input_mt_init_slots(ts->input, MAX_CONTACT_NUM,
1238                                    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
1239        if (error) {
1240                dev_err(&client->dev,
1241                        "failed to initialize MT slots: %d\n", error);
1242                return error;
1243        }
1244
1245        input_set_abs_params(ts->input, ABS_MT_POSITION_X, 0, ts->x_max, 0, 0);
1246        input_set_abs_params(ts->input, ABS_MT_POSITION_Y, 0, ts->y_max, 0, 0);
1247        input_set_abs_params(ts->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
1248        input_set_abs_params(ts->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
1249        input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
1250        input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
1251
1252        error = input_register_device(ts->input);
1253        if (error) {
1254                dev_err(&client->dev,
1255                        "unable to register input device: %d\n", error);
1256                return error;
1257        }
1258
1259        /*
1260         * Platform code (ACPI, DTS) should normally set up interrupt
1261         * for us, but in case it did not let's fall back to using falling
1262         * edge to be compatible with older Chromebooks.
1263         */
1264        irqflags = irq_get_trigger_type(client->irq);
1265        if (!irqflags)
1266                irqflags = IRQF_TRIGGER_FALLING;
1267
1268        error = devm_request_threaded_irq(&client->dev, client->irq,
1269                                          NULL, elants_i2c_irq,
1270                                          irqflags | IRQF_ONESHOT,
1271                                          client->name, ts);
1272        if (error) {
1273                dev_err(&client->dev, "Failed to register interrupt\n");
1274                return error;
1275        }
1276
1277        /*
1278         * Systems using device tree should set up wakeup via DTS,
1279         * the rest will configure device as wakeup source by default.
1280         */
1281        if (!client->dev.of_node)
1282                device_init_wakeup(&client->dev, true);
1283
1284        error = devm_device_add_group(&client->dev, &elants_attribute_group);
1285        if (error) {
1286                dev_err(&client->dev, "failed to create sysfs attributes: %d\n",
1287                        error);
1288                return error;
1289        }
1290
1291        return 0;
1292}
1293
1294static int __maybe_unused elants_i2c_suspend(struct device *dev)
1295{
1296        struct i2c_client *client = to_i2c_client(dev);
1297        struct elants_data *ts = i2c_get_clientdata(client);
1298        const u8 set_sleep_cmd[] = { 0x54, 0x50, 0x00, 0x01 };
1299        int retry_cnt;
1300        int error;
1301
1302        /* Command not support in IAP recovery mode */
1303        if (ts->iap_mode != ELAN_IAP_OPERATIONAL)
1304                return -EBUSY;
1305
1306        disable_irq(client->irq);
1307
1308        if (device_may_wakeup(dev)) {
1309                /*
1310                 * The device will automatically enter idle mode
1311                 * that has reduced power consumption.
1312                 */
1313                ts->wake_irq_enabled = (enable_irq_wake(client->irq) == 0);
1314        } else if (ts->keep_power_in_suspend) {
1315                for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
1316                        error = elants_i2c_send(client, set_sleep_cmd,
1317                                                sizeof(set_sleep_cmd));
1318                        if (!error)
1319                                break;
1320
1321                        dev_err(&client->dev,
1322                                "suspend command failed: %d\n", error);
1323                }
1324        } else {
1325                elants_i2c_power_off(ts);
1326        }
1327
1328        return 0;
1329}
1330
1331static int __maybe_unused elants_i2c_resume(struct device *dev)
1332{
1333        struct i2c_client *client = to_i2c_client(dev);
1334        struct elants_data *ts = i2c_get_clientdata(client);
1335        const u8 set_active_cmd[] = { 0x54, 0x58, 0x00, 0x01 };
1336        int retry_cnt;
1337        int error;
1338
1339        if (device_may_wakeup(dev)) {
1340                if (ts->wake_irq_enabled)
1341                        disable_irq_wake(client->irq);
1342                elants_i2c_sw_reset(client);
1343        } else if (ts->keep_power_in_suspend) {
1344                for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
1345                        error = elants_i2c_send(client, set_active_cmd,
1346                                                sizeof(set_active_cmd));
1347                        if (!error)
1348                                break;
1349
1350                        dev_err(&client->dev,
1351                                "resume command failed: %d\n", error);
1352                }
1353        } else {
1354                elants_i2c_power_on(ts);
1355                elants_i2c_initialize(ts);
1356        }
1357
1358        ts->state = ELAN_STATE_NORMAL;
1359        enable_irq(client->irq);
1360
1361        return 0;
1362}
1363
1364static SIMPLE_DEV_PM_OPS(elants_i2c_pm_ops,
1365                         elants_i2c_suspend, elants_i2c_resume);
1366
1367static const struct i2c_device_id elants_i2c_id[] = {
1368        { DEVICE_NAME, 0 },
1369        { }
1370};
1371MODULE_DEVICE_TABLE(i2c, elants_i2c_id);
1372
1373#ifdef CONFIG_ACPI
1374static const struct acpi_device_id elants_acpi_id[] = {
1375        { "ELAN0001", 0 },
1376        { }
1377};
1378MODULE_DEVICE_TABLE(acpi, elants_acpi_id);
1379#endif
1380
1381#ifdef CONFIG_OF
1382static const struct of_device_id elants_of_match[] = {
1383        { .compatible = "elan,ekth3500" },
1384        { /* sentinel */ }
1385};
1386MODULE_DEVICE_TABLE(of, elants_of_match);
1387#endif
1388
1389static struct i2c_driver elants_i2c_driver = {
1390        .probe = elants_i2c_probe,
1391        .id_table = elants_i2c_id,
1392        .driver = {
1393                .name = DEVICE_NAME,
1394                .pm = &elants_i2c_pm_ops,
1395                .acpi_match_table = ACPI_PTR(elants_acpi_id),
1396                .of_match_table = of_match_ptr(elants_of_match),
1397                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
1398        },
1399};
1400module_i2c_driver(elants_i2c_driver);
1401
1402MODULE_AUTHOR("Scott Liu <scott.liu@emc.com.tw>");
1403MODULE_DESCRIPTION("Elan I2c Touchscreen driver");
1404MODULE_LICENSE("GPL");
1405